Column

(No.18) Memory and Record

Memory plays a key role in our daily lives. Without it, we can do nothing.

If we take into account memory imperfections and the vast differences in individual capabilities, it is not safe to depend on it entirely. Ancient story tellers were skilled in memorizing events, arranging them chronologically and putting them into stories that could be retrieved at will. It is lucky that humans could invent language with abstract expressions that make it possible to record knowledge and data. New symbols acquired language structure and arranged themselves to represent concepts and philosophy. Language is important not only to record but to communicate. If we have neither name nor self identity, no family or society can exist. A person is Japanese, for example, only because
(s)he
believes
(s)he's
Japanese. In a complex society, this information is embedded into language, which has evolved in importance. The binding force of society is language, which enables people to share information. Memorized information, however, depends on the individual, where cooperative work is difficult. Individual capabilities are not equally reliable.

It was not long ago that people start recording memory. Recordings in the Altamira cave go back tens of thousands of years, but manuscripts have a much shorter history. Manuscripts have been the province of experts for a long time. Most people think they go back only a few hundred years. Compared to knowledge passed on by voice, which restricts listeners to a few hundred, the modern environment provides knowledge sharing for millions, where participants can join through spoken or written language. This extensibility is the basis of the large modern state. It is no coincidence that many countries are identified by language boundaries.

Many stories relate the conflicts encountered when people changed from memory based records to manuscript based record. In most cases, talented men of knowledge resisted written records. It is said that both Socrates and Jesus hated the written record (Alice Flaherty; The Midnight Disease, Houghton Mifflin, 2004). Celtic people, who ruled ancient Gallia, did not like to express their laws as description. As a result, they lost most of their traditional culture and history. I think Caesar wrote that people in Gallia (Celtic people) regarded writing as a corruption.

When I learned Mineralogy a long time ago, my lecturer (Dr. K) respected memory a great deal. Mineralogy is a field that inherits the Natural History that flourished in the 19th century. Many people in this field respect detailed knowledge of everything that exists in Nature. They regard both memory and records as crucial. Dr. K was a member of the international committee of mineralogy, which holds the power to authorize new minerals. There were more than 4000 minerals registered in the world. Each time a new mineral was introduced, committee members checked characteristics to determine if it met requirements as a new mineral. Dr. K knew every mineral, including their specific characteristics, so he could immediately make a decision. Detailed examinations were followed, but Dr. K's quick decisions impressed many. If onsite decisions were required, Dr. K was unequaled. He checked minerals for morphology, color, coexistence with other minerals, locality, chemical composition, crystal structure, correspondence with geography, and resistance to weathering --- so many items were checked on the spot.

A powerful expert like Dr. K is rare in society, so a system that depends on experts is expensive. Only a limited number of executives can use this knowledge. Figure 1 describes this status.

Fig. 1 Information cost and access speed

How information is used depends on the richness of contents and how fast we can retrieve and access the needed information. Conventional methods that depend on experts are expensive. Today's retrieval systems make full use of the Web, replacing conventional methods.

The importance of memory resides in its usage and applications. Stored information itself does not help, other than providing boasting rights. To be useful, a retrieval function is required. When the means for retrieval were limited in the past, information storage was just a dumb pile, too lumpish to do anything with. If it was stored in the brain, it could be accessed instantly via language, image, smell, or any sense or key. With new mineral applications, each check item is a possible key. Beyond that, results retrieved by multiple keys often hint at something new.

Recent research on the human brain suggests that the human memory system uses many links. For example, the Japanese word, and where both have the same pronunciation and the same meaning, are stored at different locations in the brain. When the system is normal, all of this information works together; it is difficult to realize that each key resides in a different place. Therefore, if unified correlation fails, you can read Kanji but cannot understand it, or cannot pronounce it, or cannot understand the meaning. Various symptoms emerge if the system fails to work properly. It is interesting to know how information can be retrieved. The access route seems unique to each person, which is the reason group discussions can be so useful.

Among the varied types of information, language is the most advanced to represent abstract concepts. Among languages, Chinese allows the most condensed expression within limited space. I have the impression that Chinese requires just 30% to 50% the space required by English. Using condensed Chinese expressions, a person can read up to tens of thousands of characters a day. This corresponds to the order of 10 4 bytes. On the other hand, we can scan one megabyte of compressed images per second. This corresponds to 5 x 10 10 bytes per day if we disregard fatigue of the person perceiving image. For voice data, 10 hours continuous exposure computes to 5 x 10 5 bytes data. In Figure 2, "Figure" indicates drawings images. Figure 2 summarizes the volume of data that a person can accept in a day.

Fig. 2 Maximum amount of information perceived by a human per day.

Information has various forms. In business, text has been the most common form. Text can express abstraction and adapt itself for storage and retrieval. But it is not always good for passion. Inefficient information like images can now be handled fairly easily by electronic representation.

The power of recorded text resides in the power of language. The proper noun Junichiro Koizumi, for example, represents only one person, but the meaning is not only a Homo Sapien. His social status, his way of thinking, his talent and attraction, or his disgust, are all included. Considering his position as prime minister of Japan, he sometimes represents Japan, or represents the state man of Japan. Because of these multiple attributes, we can share deep meaning. In communication, this deep meaning is shared.

Language comes at a high cost, because only humans can create sentences after human processing. However, we do not pay too high a cost for image information. It appeals to humans through simple observation.

Text contents are easy to reflect compared with images or music. We need to preserve them. This is the main reason we keep photo albums at home. How they impress us depends greatly on size. Music also remains in memory for a long time. Music learned as a teenager stays in memory. A composer has memory ready to retrieve in seconds. Music is often represented as signal strings, which provide key tags for retrieval. Music representation itself is fuzzy; however, it has the potential to represent abstract contents. Combined with a powerful key search engine, music may have broader applications in the future.